Many app notifications are actually delivered from your phone operating system's manufacturer - for example on an iPhone, notifications are pushed to your phone from Apple servers, and on an Android, notifications are pushed to your phone from Google servers.

This is done to reduce battery life - the Apple / Google servers combine updates from multiple apps into one update for your phone so that it can just receive one message instead of lots of them.

The firewall is blocking, e.g., Facebook.com, but not blocking the notifications from Apple or Google. However if you click on a notification and try to go to Facebook, the app won't be able to download it.

Chances are the places that are blocking Facebook is using the very worst blocker that's out there. Think of it as a mono signal (which is a one direction signal) and a stereo signal (which is a signal going both ways). They're probably just spanning a mono ad block, which has got to be the cheapest thing ever, over large, expansive plots of land so that they don't have to pay anything at all the keep a bunch of people from connecting to the internet on their end.

I think you've answered my question, but not totally sure yet. So are you saying the Chinese government is mostly just putting up a front? Their Firewall is one of the most controversial things regarding the Internet and yet it's incredibly useless for the censorship that the government is trying to impose.

I'm not totally sure if the same thing happened to me at school (where YouTube and Facebook are blocked) but I think it has. Does anyone use proper two-way blocking or is it just too expensive to be practical?

Nothing what this guy said is good. The first guy has is spot on. China just blocks facebook and does a pretty good job if it. It doesn't really care about any notifications you get because facebook is still blocked. Why don't you just get a VPN and be done with it?

They're not putting up a front per say, they're just doing the bare minimum they possibly can to block an entire country from using the internet. The lowest form of blocking is just to keep users from interacting with it, not from the internet reaching the users themselves (because that's pretty much impossible to do effectively).